Growing healthy seedlings and transitioning them outdoors involves careful handling at each stage of development. This guide will walk you through the essential techniques for pricking out, potting on, and transplanting seedlings to ensure they thrive in your garden.
Pricking Out Your Seedlings
“Pricking out” refers to the process of separating seedlings that have grown closely together and replanting them into individual pots or plugs. Begin this process as soon as the seedlings are large enough to handle, typically when they have developed their first true leaves.
- Prepare Containers: Choose plug trays or small pots filled with high-quality, well-draining potting mix.
- Separate Seedlings: Carefully remove seedlings from their original tray and gently tease them apart, preserving as much of the surrounding mix around the roots as possible. Work with small batches to avoid drying out the roots.
- Planting Seedlings: Use a pencil or your finger to create a hole in the potting mix for each seedling. Always handle seedlings by their leaves, not the delicate stems. Gently insert the roots into the hole and firm the soil around them. If your seedlings are leggy (elongated and weak), you can bury part of the stem to help support them.
- Watering: After planting, water the seedlings gently with a fine rose watering can or hose. Don’t worry if they flatten slightly; they will recover quickly.
Choosing the Right Containers: Plugs vs. Pots
- Plugs: Small plug trays are ideal for fast-growing salad crops that will be transplanted within a few weeks.
- Pots: Larger seedlings, like those from the cabbage or onion families, or tender crops such as tomatoes and peppers, benefit from individual pots. These may need to be potted on again before moving them outdoors.
Preparing Seedlings for Planting Outdoors
Seedlings must be gradually acclimatized to outdoor conditions before transplanting. This process, called “hardening off,” strengthens them by exposing them to sun and wind.
- Watering: Keep the potting mix moist, but be careful not to overwater. If your seedlings are in a greenhouse or cold frame, open the vents on warm days to improve ventilation and reduce mold risk.
- Soil Temperature: Cool-season crops like lettuce and peas can be planted outside when the soil reaches around 50°F (10°C). Use a garden planner to determine the best time for transplanting based on your location.
- Hardening Off: Gradually introduce seedlings to outdoor conditions by placing them outside for increasing periods over the course of a week or two. If you’re using a cold frame, open the vents a little more each day to let the seedlings adjust to temperature and humidity changes.
How to Transplant Seedlings
Transplanting seedlings into your garden requires prepared soil, enriched with compost or other organic matter.
- Prepare the Garden Bed: Make sure the soil is loose, well-drained, and free of weeds.
- Spacing: Lay out your seedlings, ensuring proper spacing (you can use a tape measure, or space by eye). Using a hand trowel or dibber, create holes in the soil.
- Planting: Gently remove the seedlings from their containers, ensuring the rootballs remain intact. Place each seedling into its hole and firm the soil around it. If the seedlings are tall or leggy, plant them deeper, but avoid burying the lowest leaves.
- Watering: Water the newly transplanted seedlings well to settle the soil around their roots. Ensure the rootballs are moist before planting; if needed, soak them in water before planting.
Protecting New Transplants
Young transplants are vulnerable, so consider protecting them with row covers or garden fleece. This provides warmth, shields them from wind, and deters birds. Secure the covers tightly to avoid wind displacement and remove them once the weather improves. Keep an eye out for pests like slugs and snails, and consider using beer traps to prevent damage.
Final Thoughts
Successfully transplanting seedlings marks a key milestone in the gardening season. By carefully managing each stage—from pricking out to hardening off and transplanting—you can help ensure a strong, healthy crop. Share your experiences and tips in the comments, and happy gardening!